1. Field of Invention
The present invention relates to a dispenser and an applicator that leaves two reactive substances separate until time of use. Such uses may include a tooth whitening or polishing system, a treatment for skin and other dermatologic applications, a delivery system for glues or other commercial compounds wherein the substrates are separate until delivery, pharmaceuticals, hemostatic agents, sealants and many other uses. With respect to tooth whitening or polishing in particular, one of the two substances may be hydrogen peroxide and/or carbamide peroxide that is isolated from the other of the two substances, such as sodium bicarbonate. The substances are subsequently mixed together at the time of use, for and during application of the mixture on the targeted surface.
2. Description of Related Art
Peroxide is the active ingredient in many tooth whitening products. There are two types—carbamide peroxide and hydrogen peroxide—both work similarly. The peroxide breaks down into H20 and a free radical oxygen (a highly reactive oxygen with an unpaired electron), allowing the reactive oxygen to contact the enamel layer of the teeth, thereby oxidizing stain and bleaching the tooth. The reactive oxygen can travel through the enamel of the tooth into the dentinal structure that contains the color pigments. The color pigments are vaporized by the oxidation procedure and thus lightening the overall tooth. Used properly and in safe concentrations, peroxide will not damage the enamel or any other part of teeth Carbamide peroxide breaks down into hydrogen peroxide and urea which then continues to breakdown into ammonia (NH3). Hydrogen peroxide is very unstable and can be stabilized either through formulation, i.e. carbamide peroxide or through a hermetically sealed delivery system such as a strip, a dissolvable film or an ampoule.
A mixture of hydrogen peroxide based whitening compounds with sodium bicarbonate produces notable effervescence in whitening if used immediately after mixing them together. As a result, the efficacy of hydrogen peroxide based whitening compounds is enhanced because of the mixing with the sodium bicarbonate. This is a result of the sodium bicarbonate raising the ph above the threshold of a ph of 9.5 which creates the most reactive perhydroxyl molecule vs. a free radical oxygen formation. The perhydroxyl molecule at the time of use is ideal for tooth whitening as a greater oxidation reaction occurs.
The elements necessary for tooth whitening is the concentration of the hydrogen peroxide and the amount of time the hydrogen peroxide is on the teeth. Teeth whitening systems contain different strengths of peroxide. Those with higher concentrations of peroxide can produce faster, more dramatic whitening of teeth. However, there is an increased risk of creating temporary but uncomfortable tooth sensitivity with the higher concentration formulas. Products with a lower concentration of peroxide carry less risk of unpleasant side-effects, but they do not whiten as quickly as those with higher concentrations. Successful tooth whitening without sensitivity occurs with high frequency of use vs. high concentration of the whitening gel that can cause sensitivity and harm the soft tissues.
Some teeth whitening products are Ph buffered, to reduce the likelihood and severity of side effects of the low ph associated with carbamide peroxide gels. The carbamide peroxide gels can be ph buffered up to a certain amount to reduce the side effects but cannot be packaged higher than a ph of 5.5. for stability reasons. Carbamide peroxide breaks down to hydrogen peroxide combined and urea (an aqueous solution This breaks down even further to NH3 (ammonia) and we don't know the long term consequences of ammonia in the mouth for a long period of time. Carbamide peroxide is found in over-the-counter tray and gel systems and professional tooth whitening tray and gel formulas, light-activated tooth whitening gels and whitening toothpastes. Tooth whitening products containing carbamide peroxide typically range from concentrations of less than 10% to about 22%, which has the equivalent of hydrogen peroxide of 3% and 7.3% respectively. Professional products may contain as much as 35% carbamide peroxide which has an equivalent of 12% hydrogen peroxide. The new whiteners today use hydrogen peroxide in a unique delivery system to avoid the breakdown products, i.e. the ammonia breakdown by-product of the carbamide peroxide gel.
Hydrogen peroxide is found in whitening strips, dissolvable film, and paint on whiteners like an ampoule. These unique delivery systems create a hermetically sealed environment, thus not allowing oxygen in or out keeping the hydrogen peroxide gel stable until used.
Sodium bicarbonate (baking soda) helps clean teeth, freshen breath and neutralize mouth acids that can destroy tooth enamel. Used for decades for dental care, the FDA recognizes it as safe. It has been mixed conventionally with whitening compounds to whiten teeth. It has the effect of raising the ph of tooth whitening gels and creates a highly reactive perhydroxyl molecule.
Magnesium peroxide is recognized as an oxidizer that whitens teeth and aluminum oxide is recognized as a tooth surface polisher.
A need to improve conventional techniques for whitening teeth is discussed in U.S. Pat. No. 7,201,577, U.S. Pat. No. 6,929,475, U.S. Pat. No. 6,726,482 B2 and U.S. Pat. No. 7,070,413.
Various approaches have evolved for at-home teeth whitening procedures (without the need for the dental practitioner). Among the early at-home teeth whitening systems was a paste or gel containing carbamide peroxide that was placed in a dentist administered tray or an over-the-counter boil and bite plastic guard. The gel or paste was applied to tooth surfaces by, for example, the placement of the tray in the mouth, a toothbrush, a cotton swab, etc., as discussed in U.S. Pat. No. 7,070,413.
There are many well-known two-part substrates that, when combined or mixed, form a desired reaction. Such materials may be sealants, adhesives, hemostatic agents, whitening agents, and numerous other equivalent two-part materials that when combined form a material having desired properties, as discussed in U.S. Pat. No. 6,929,475.
U.S. Pat. No. 6,929,475 discloses a single use applicator of chemical or medicament material to be applied to a surface to be treated. The material, which may be a stable, inactive solid powder, is placed on an absorbent portion of the applicator. A liquid activating agent is released onto the absorbent portion of the applicator to activate the otherwise stable, inactive solid powder. The activated powder is applied to surfaces of the tooth with the applicator to whiten and polish the tooth. The absorbent portion may be a cotton swab.
Conventional dispensers that dispense contents from bottles and tubes trap significant amounts of their contents in corner regions. Users therefore, are generally unable to retrieve such trapped contents. Such dispensers may leak if not sealed securely.
It would be desirable to keep two reactants isolated from each other within a dispenser, yet allow them to blend together to form a blended mixture at the time of desired application of the blended mixture to the tooth being treated. It is further desired to apply the blended mixture to the treatment area of the tooth in a direct and even manner of application.
It is also desired to minimize an amount of the contents of the dispenser that cannot be retrieved by a user by preventing the contents from becoming trapped at corners of the dispenser. It is further desired to securely seal the dispenser to prevent leakage.